SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97fe3daebdb3b6cb994e3abf6b2fe901e69469dc6f0b55d9027e60ef05c18db7' 
  AND token = 'wpz6kLEG7V0rSfN9vSPQURqmNuhpkFKO0RJ/jDjvFAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}